The purposes of this study include 1) determine clinical utility of clinical observation of aberrant movement patterns during functional trunk and pelvic movements in asymptomatic individuals and patients with non-specific low back pain, 2) characterize trunk neuromuscular control in asymptomatic individuals and patients with non-specific low back pain, and 3) determine the appropriate physical therapy intervention that addresses trunk neuromuscular control deficits in patients with non-specific low back pain.